Means for the submerged introduction of a fluid into a body of liquid

ABSTRACT

Improved system for the submerged introduction and distribution of a fluid into a body of liquid, for instance in an apparatus for the hydraulic upflow classification and/or desliming of metallurgical pulps or the like in a teeter bed, employing selfcleaning nozzles in the form of resiliently yieldable check valves.

United States Patent 1 Figliola et al.

[451 Mayl6, 1972 [54] MEANS FOR THE SUBMERGED INTRODUCTION OF A FLUIDINTO A BODY OF LIQUID [72] lnventors: Patsy J. Figliolmstamford; DouglasJ. Mc-

Callum, Jr., Norwalk, both of Conn.

[73] Assignee: Dorr-Oliver Incorporated, Stamford,

Conn.

[22] Filed: July 24, 1970 [2]] App]. No.: 58,070

Related U.S. Application Data [63] Continuation-in-part of Ser. No.699,012, Jan. 1 1,

1968, abandoned.

[52] U.S. Cl ..137/543.17, 137/592, 239/453, 222/496 [51] Int. Cl ..B05bl/32, F1 6k 15/06 [58] Field of Search 1 37/592, 541, 543.17; 222/496,

[56] References Cited UNITED STATES PATENTS 1,111,993 9/1914 Carder..239/453 X 1,628,823 5/1927 Chester et a1. ..239/453 2,006,369 7/1935Sargent ....222/542 X 2,446,918 8/1948 Goddard... ....239/456 X2,608,376 8/1952 Adams ...137/543.17 2,784,737 3/1957 Kelly 1 37/543. 17 2,835,269 5/1958 Seymour ....222/542 X 2,936,958 5/1960 Shames et al.....239/543 X 2,986,382 5/1961 Langdon ....239/543 X 3,379,213 4/1968Billington ..137/543.17 X

Primary ExaminerWilliam R. Cline Att0rney-T. M. Jablon and Burtsell J.Kearns 5 7] ABSTRACT Improved system for the submerged introduction anddistribution of a fluid into a body of liquid, for instance in anapparatus for the hydraulic upflow classification and/or desliming ofmetallurgical pulps or the like in a teeter bed, employing self-cleaningnozzles in the form of resiliently yieldable check valves.

32 Claims, 21 Drawing Figures Patented May 16, 1972 ,7 3,662,781

4 Sheets-Sheet 1 INVENTORS. PATSY J. F'IGLIOLA DOUGLAS J. MC CALLUM,

ATTORNEY.

Patented May 16, 1972 3,662,781

4 Sheets-Sheet 4 FIG. l6 FIG. I? W34 l i \\l INVENTORS'. PATSY J.FIGLIOLA DOUGLAS J. MC CALLUM BY WW 2 2 %n ATTORNEY.

MEANS FOR THE SUBMERGED INTRODUCTION OF A FLUID INTO A BODY OF LIQUIDThis is a continuation in part of an application Ser. No. 699,012, nowabandoned, filed Jan. 11, 1968 by Patsy J. Figliola' et al.

This invention relates to means comprising nozzles for the submergedintroduction and distribution of a fluid for instance water or air, intoa body of liquid.

The invention is herein illustrated as embodied in apparatus foreffecting the hydraulicor hindered settling classification and/ordesliming in a teeter bed of metallurgical pulp, forming the subjectmatter of US. Pat. No. 3,485,365 to Leon D. Keller disclosing but notclaiming this nozzle.

In the operation of such classification apparatus, feed pulp iscontinuously supplied to a tank, and exposed to a rising flow ofhydraulic operating water maintaining the teeter bed. The upflow rate isso controlled as'to cause an undersize fraction of solids smaller than acritical size to pass from the tank by way of overflow, while anoversize fraction of solids larger than the critical size is removedfrom the bottom zone of'the teeter bed.

In the past, such classification operations have been carried out withthe aid-of a system of diffuser pipes provided in the bottom zone of theteeter bed, with jets of teeter water emanating from a multitude oforifices in these pipes.

A problem encountered with such-a system was due to the fact that alarge number of small orifices were required in the pipes to provide adesired uniformity of distribution. These small orifices, however, weresubject to plugging requiring relatively frequent shutdowns andoverhaul.

Plugging of these orifices might be minimized or discouraged by the useof a smaller number of larger orifices. This in turn would present theproblem of concentrated upflow streams contrary to the requirement ofuniform water distribution;

It is, therefore, a main object of this invention to provide aninductionand distributing system for teeter water, that is nonpluggingin the presence of the slurry solids even while providing uniformdistribution and a uniform teeter bed.

Another object is to provide such non-plugging teeter water inductionsystem that is efficient and economical in regard to relativelyminimizing the amount of teeter water required for maintaining a desiredsolids separation, thereby also relatively increasing the solidsconcentration in the separated solids fractions.

Still another object is to provide such a non-plugging teeter waterinduction system that can be readily installed at relatively low cost,or substituted to replace the above-indicated jet orifices. I j

Still another object is to provide a non-plugging teeter water inductionsystem particularly well suited for use in the hindered settlingclassification apparatus described in the aboveidentified patent of LeonD. Keller US. Pat. No. 3,485,365. Briefly, that apparatus comprises atank having the preferred water induction means of the present inventioninstalled in the bottom zone of the teeter bed. In addition, there is arotary rake structure operating directly above the zone of waterintroduction. In the operation of this apparatus, the undersize fractionor slimes are delivered by overflow, while the rake structure aids inconveying coarse solids across the area of hydraulic agitation to acentral quiescent collecting zone from which the resulting oversizefraction is removed as underflow through an outlet inthe tank bottom ata controllable rate and high solids concentration.

To attain the foregoing objectives this invention proposes to avoid theabove-indicated use of the discharge orifices by the provision upon thepipes or distribution headers of nozzles that are non-plugging orself-cleaning, in the nature of resiliently yieldable check valvesserved by a water supply of adequately high pressure. A preferredspring-loading tension in the nozzles is readily adjustable relative tothe water supply pressure, to establish a desired teeter condition. Thenozzle or valve unit is so constructed that the relative amount ofspring compression or valve through flow resistance is rendered visibleexternally of the valve. When in operation, this nozzle is surrounded byan area or zone of uniform intense hydraulic agitation due to the teeterwater emanating from the nozzle uniformly in all directions andpreferably in a horizontal plane. While in operation, this nozzle orvalve unit is selfcleaning, but will close tightly in case of an unduedrop or failure of the supply pressure.

The nozzle unit of this invention comprises a valve housing in the formof a cylindrical hollow open-ended body closed at one end by a valvemember or valve plate having a stem extending into the housing coaxialtherewith. Yieldable restraining means effective between the stem andthe housing urge the valve plate onto its seat.

According to one feature, the valve stem is lengthwise adjustable andsecurable relative to the valve plate for varying the seating pressureexerted upon the valve member by the restraining means or spring, withthe outwardly projecting end portion of the stem providing a relativemeasure of the seating pressure.

Preferably, the stem extends through the valve member in threadedconnection therewith, so that the valve seating pressure or through-flowresistance of the nozzle unit may be varied conveniently by rotating thevalve member relative to the stem.

Another feature lies inthe provisionof a compression coil springsurrounding the valve stem within the valve housing to exert the valveseating pressure, constructed and arranged in such a manner as tominimize any flow obstruction within the housing.

According to still another feature, the compression coil spring isspecially shaped to serve the dual purpose of guiding the stem withinthe spring, and guiding the spring within the valve housing.

Still another feature lies in the provision and manner of mounting of anannular valve seat consisting of a resilient elastic material.

Other features and advantages willhereinafter appear.

As this invention may be embodied in several forms without departingfrom the spirit or essential characteristics thereof, the presentembodiment is therefore illustrative and not restrictive, since thescope of the invention is defined by the appended claims rather than bythe description preceding them, and all changes that fall within themetes and bounds of the claims, or of forms that are their functional aswell as conjointly cooperative equivalents, are therefore intended to beembraced by those claims.

FIG. 1 is a vertical sectional view of an upfiow classificationapparatus embodying the improved system for introducing the teeterwater, featuring the use of valve type delivery nozzle units.

FIG. 2 is a plan view of the apparatus of FIG. 1, showing more clearlythe arrangement of a system of distributing headers with the nozzleunits.

FIG. 3 is a greatly enlarged fragmentary side view of a header,illustrating the operation and effectiveness of the nozzle units in ateeter bed.

FIG. 4 is a further enlarged vertical sectional view of the nozzle unitshowing a coil spring loaded valve member.

FIG. 5 is a cross-section taken on line 5-5 in FIG. 4, clearly showingone end of the coil spring attached to the valve member.

FIG. 6 shows the nozzle unit of FIG. 4, illustrating a manner ofadjusting the tension of the spring.

FIG. 7 shows the nozzle unit containing one embodiment of thecompression coil spring, having the dual functions of guiding the stemas well as the spring.

FIG. 8 is a cross-sectional view taken on line 8-8 in FIG. 7.

FIG. 9 is a cross-sectional view taken on line 9-9 in FIG. 7.

FIG. 10 shows the nozzle detached similar to FIG. 7 with I anotherembodiment of the coil spring, effective to guide the stern as well asthe spring.

FIG. 11 is a cross-sectional view taken on line 11-11 in FIG. 10.

FIG. 12 is a cross-sectional view taken on line 12-12 in FIG. 10.

FIG. 10a is a detail cross-sectional view taken on line 10a- 10a in FIG.10.

FIG. 10b is a detail cross-sectional view taken on line 10b 10b in FIG.10.

FIG. 10c is a detail cross-sectional view taken on line 10c I in FIG.10.

FIG. d is a detail cross-sectional view taken on line 10d- 10:1 in FIG.10.

FIG. 13 shows the nozzle unit similar to FIGS. 7 and 10, containingstill another embodiment of the compression coil spring, representing acombination of the embodiments of FIGS. 7 and 10.

FIG. 14 is a cross-sectional view taken on line 14-14 in FIG. 13.

FIG. 15 is a cross-sectional view taken on line 15-15 in FIG. 13.

FIG. 16 is an exploded view of the nozzle unit, illustrating the mannerof assembly.

FIG. 17 shows the nozzle unit assembled.

The apparatus herein exemplifying the invention, comprises basically atank 10, an induction system 11 at the bottom of the tank forintroducing teeter water into the body of pulp in the tank to maintain ateeter bed, and a rotary rake structure 12 having rake arms operating ina plane directly above and close to the induction system, in a bottomzone of the teeter bed. The water rising from the induction systemeffects the separation of the pulp into an undersize fraction whichoverflows, and an oversizeor coarse fraction to be discharged asunderflow through an outlet in the tank bottom. The rotating rake armssweeping over the induction system cause even relatively large andnon-teeterable particle size contained in the pulp mixture to beconveyed to a central collectionand outlet zone capable of deliveringthe underfiow fraction in a state of high solids concentration.

The tank may be one that has a cylindrical wall 13, a shallow conicalbottom 14, and a peripheral overflow receiving launder 15. The tankitself is spaced from the ground by supporting piers or columns 15providing access to the underside of the tank and to a sump 16delivering the underflow fraction of the pulp through a dischargecontrol valve 17.

Drive mechanism 18 for rotating the rake structure as well as supportingthe same, is mounted upon an overhead truss structure or bridge 19endwise supported by the wall of the tank. The bridge also supports atits underside a feed well 20 which may be of the type shown in thepatent to Fitch U.S. Pat. No. 3,006,474 and further illustrated in FIG.I, for delivering feed pulp to the tank. A supply duct for the feed wellis indicated at 21.

The rotary rake structure itself being of a known construction has ashaft 22 depending from the drive mechanism, and rake arms 23 extendingfrom the shaft at an elevation above and close to the induction system11, to operate in the bottom zone of the teeter bed. Preferably, thedrive mechanism is of the kind that allows the rake structure to beraised or lowered.

The teeter water induction system in this embodiment may comprise anannular main header 24 shown to be resting upon the tank bottom, andhaving symmetrically arranged supply connections 24 and 24. Radiallyextending tubes or subheaders 25 are placed astride the main header,communicating therewith through connections 25. The sub-headers extendat a slope substantially conforming to the conical shape of the tankbottom.

The radial sub-headers carry non-plugging or non-clogging novel teeterwater induction nozzles 26 suitably spaced from one another along thelength of the sub-headers and preferably so arranged that the nozzles ofeach sub-header are staggered with respect to the nozzles on eachadjoining subheader. When in operation, that is when delivering teeterwater, each of these nozzles may become the center of a circular area orisland C of hydraulic agitation or churning (see FIG. 3). All theseareas C" are contained in a general upflow area defined by the outerdiameter D-I of the tank and the inner diameter D-2 which in turndefines a non-agitated central area surrounded by the upflow area. Thus,the other ends of the radial sub-headers 25 may terminate at the wall ofthe tank, while the inner ends may terminate at the periphery of thecentral non-agitated quiescent area or oversize solids collecting zone.

A non-plugging nozzle unit, according to this invention is of the checkvalve type having a valve closure member or-plate spring loaded, withthe spring pressure adjustable for varying the discharge flow resistanceof the valve relative to the pressure of the teeter water supply. Oneform of the nozzle is shown in FIGS. 4 and 5, while the manner of itsoperation within the classifying, sizing-, or desliming apparatus iswell illustrated in FIG. 3.

As shown, the nozzle unit of this invention comprises a cylindricalhollow open-ended valve body 27 of substantial wall thickness andpreferably consisting of a plastic composition material. The lower endof this valve body has an internal thread tightly engaging the externalthread of an upwardly directed nipple or neck 28 on the sub-header 25.The upper end of the valve body has an internal downward facing orinverted shoulder 28a concentric with the vertical axis of the nozzle.The outer peripheral top edge portion of the valve body is formed withan annular recess 29 wherein is seated an elastic or rubber O-ring 30.When stretched and snapped into this recess, the resilient material ofthe O-ring provides a seat upon which a valve plate 31 may close downtightly. The cross-sectional profile of recess 29 and that of the ringmember 30 conform to each other, with the ring member snugly seated andsecurely held in place by the slightly outwardly overhanging peripheraledge indicated by its diameter D-3. A coil spring 32 under compressionexerts seating pressure upon the valve plate, the ends 32a, and 32b ofthe spring being confined respectively by the inverted shoulder 28a andby the lower end or head of a valve stem in the form of an invertedscrew bolt 33 threaded into the valve plate 31, and secured by lock nut34. The end 32b of the spring is in the form of a constricted terminalportion or open terminal loop closely hugging the bolt, and retained bythe relatively small head 32c of the bolt. The valve plate may consistof a plastic composition material similar to that of valve body 27.

According to FIG. 6 the valve seating pressure exerted by the spring isadjustable by loosening the lock nut 34, then holding the screw bolt 33against rotation as indicated by a screw driver 33a engaging the outerend of the bolt, while turning the valve plate up or down upon thethread of the bolt. This will respectively decrease or increase thespring pressure, and correspondingly vary the discharge flow resistanceof the nozzle relative to the pressure of the teeter water supply. Thentightening the lock nut against the valve plate will secure theadjustment. By providing proper adjustment of the spring pressure, aswell as an adequately high teeter water supply pressure, there may beestablished a uniform delivery rate of teeter water from all the nozzleunits, irrespective of the differences in static head against which thenozzles must operate, such differences being due to the slopingarrangement of the sub-headers 25. Also, with the proper springadjustment this nozzle is non-plugging and self-cleaning even thoughexposed to the solids in the pulp.

The nozzle unit detached from the supply header, as shown in FIGS. 7 to15, has a compression coil spring shaped to provide axial guidance forthe valve stem and valve closure member.

Therefore, in this embodiment, each wire end portion of the spring isformed into a constricted loop or coil of reduced diameter providingaxial guidance relative to the spring, the spring itself being guided inthe cylindrical bore of the valve housing. While thus maintainingconcentricity and limiting lateral sway, the spring will neverthelessallow for self-adjustment of the valve closure member upon the valveseat or resilient sealing ring.

Accordingly, a compression coil spring 35 in FIG. 7 comprising a bodyportion formed by coils 36, is loosely fitted into the bore of the valvehousing. The end portions of the spring are formed by terminal loopportions 37 loosely encircling the stem 37 (see FIGS. 8 and 9). The stemmay be in the form of a simple bolt in threaded connection with thevalve closure member 37'. Each of the loop portions 37 in turn comprisesa curved or substantially half round portion 38 of a radius similar tothat of coils 36, a loop 39 of much smaller diameter encircling thestern, a first straight transverse portion 40 connecting the curvedportion 38 tangentially with the inner end of the loop 39, a secondstraight transverse portion 41 extending tangentially from the outer endof the loop 39, substantially in line with the straight portion 40, andhaving a right angle terminal portion 42.

Thus, the stem is guided in the end loops 39, while the spring itself isguided in the bore of the valve housing. As noted furthermore from FIGS.8 and 9, the terminal portion 42 and the corner 43 opposite thereto ofthe curved portion, are slightly outwardly disposed beyond the diameterof coils 36 in shaping the spring, thus to insure that the curved endportion 38 may rest securely upon the adjacent coil 36 of the springwhen under compression. This spring has a dual function permittinguninhibited axial movement of the stem and valve closure member in theoperation of the nozzle, while limiting lateral sway of the stem, andinsuring uniform distribution of the liquid in all directions. The otherend of the spring engages shoulder 37c. The terminal loops are alsodesignated by the smaller diameters d-l and d-2 respectively.

In the embodiment of FIG. 10, a compression coil spring 44 has a fullsize coil 45 formed at each end (see also FIGS. a and 10d, and anintermediate or body portion formed of similar full size coils 46. Theintermediate portion is connected to each respective end coil 45 througha constricted coil 47 of substantially smaller diameter encircling thestem. Thus, the stem is guided by the two constricted coils 47, whilethe spring itself is guided in the bore of the valve housing by the endcoils 45, and as the case may be also by the intermediate coils 46. Theconstricted coils are also designated by diameters d-3 and (1 4.

The embodiment of FIG. 13 shows a compression spring representing acombination of the characteristics of the embodiments of FIG. 7 and 10,in that the one or upper end of the spring is formed similar to one ofthe end portions of the spring of FIG. 7, while the other or lower endis formed similar to one of the end portions of the spring of FIG. 10.The respective constricted springs are designated by diameters 11-5 andd-6.

In a practical instance, with adequate water supply pressure available,all nozzles may have the pressure or compression of the springs adjustedto the same amount as indicated by the length 1" of the upwardlyprotruding end portion of the stem. For example, with spring pressure ofall the nozzles set at 5 lbs. and a supply pressure of about 40 lbs.,substantially uniform delivery rates may be obtained from all the nozzleunits thus maintaining a teeter bed of suitable characteristics, evenwith the sub-headers 25 inclined as shown. The nozzle will be effectiveeven when submerged in a bed of sand, to maintain a teeter operation.Another application is in a slurry storage tank as exemplified in thepatent to Kadden, US. Pat. No. 2,151,848, wherein means for thesubmerged introduction of air are mounted on a rotary structureoperating to prevent the packing of solids on the tank bottom.

In the present example of classification apparatus, an upflow rate ofteeter water may be established, sufficient to cause a desired undersizefraction to report to the overflow of the tank, yet insufficient to keepthe oversize fraction solids in a state of teeter, and insufficient toprevent their accumulation in the bottom zone of the teeter bed.

In the operation of the apparatus, the rake arms of the rotating rakestructure sweeping over the nozzles in the bottom zone of the teeterbed, positively move the oversize solids from the hydraulic influence'ofone nozzle to the influence of the next nozzle and so on (see FIG. 2).While thus in transit towards the central outlet area, the oversizefraction solids are repeatedly agitated or churned and scrubbed free ofslimes, while exposed to the direct action of the teeter liquidimmediately around the nozzles before reaching the quiescent collectionarea D-2 for withdrawal. A clean separation of the fractions is thusattainable, as well as a high solids concentration of the underflow.Furthermore, because of the positive mechanical conveying action of therake structure, the consumption of teeter water is held to a practicalminimum, thereby rendering the overflowing undersize fraction also in astate of relatively high solids concentration.

In one important application of desliming, the nozzle units according tothis invention will operate effectively to remove finely divided silicaconstituting the slimes in iron ore pulp or taconite that is to beprepared for pelletizing and subsequent smelting of the pellets orbeneficiated ore in the blast furnaces. The presence of any silica inthe blast furnace is objectionable, so that any improvement in theefficiency of washing out these slimes results in significantly improvedblast furnace operation, with an improved iron product resultingtherefrom.

From the foregoing it will be seen that the present invention provides asystem of non-plugging nozzle units for the submerged introduction of afluid, for instance, of teeter water in the upflow classificationtreatment of pulp. This nozzle unit is of simple inexpensiveconstructionhaving readily accessible means for spring adjustment, and a means forindicating the relative amount of spring tension or valve seatingpressure. Valve seating pressure is provided by a compression coilspring so shaped and mounted within the nozzle body as to present aminimum of flow obstruction. In operation, these nozzle units arecapable of providing uniform teeter water distribution, thus relativelyminimizing the amount of teeter water required, as compared with theearlier orifice type teeter water distribution systems.

Moreover, the compression spring if formed with constricted end coilportions will perform a double guide function which limits lateral swayof the valve member.

FIG. 16 is an exploded view of the nozzle unit illustrating the mannerof assembly, which requires the spring 32 and the bolt 33 to be insertedfrom the inlet end of the housing member 27, the bolt to be screwed intothe valve plate 31 which is applied to the opposite end of the housingmember, and secured by lock nut 34. When assembled as shown in FIG. 17,the spring is adjusted to a suitable valve closing pressure so thatunder normal conditions it will yield to a suitable water supplypressure, but will cause the valve plate 31 to close instantaneouslyupon the rubber sealing ring 30 when the water pressure drops or ceases,so that pulp solids will not enter the nozzle. With the nozzle closed,and the valve plate engaging the sealing ring, there is a suitableclearance C" between the valve plate and the housing member.

It will furthermore be understood that each of the elements of thenozzle system of the nozzle unit per se, or two or more elementstogether may also find useful application in other types of apparatusfor the hydraulic agitation or classification of pulps or slurries.

While the nozzle unit of this invention has been illustrated anddescribed as a check valve type of delivery nozzle unit, containing acompression coil spring surrounding the stem which is longitudinallyadjustable relative to the valve member, it is not intended to belimited to the details shown since various modification and structuralchanges may be made without departing from the spirit of the presentinvention.

We claim:

1. A nozzle for the delivery of a liquid under pressure, which nozzlecomprises a valve body having a vertical axial bore with an inlet endand an outlet end, and with an internal annular shoulder formed at theoutlet end of said bore,

a valve closure member for closing said outlet end,

a stem having an outer end portion connected to said closure member,said stem extending into said bore, and having stop means at its innerend,

and a compression coil spring inserted through the inlet end of saidbase, surrounding said stem and confined between said annular shoulderand said stop means, and effective to allow liquid under pressure to beemitted, and to urge the closure member into closing position when theliquid pressure drops,

said spring being formed with a constriction at each end encircling thestem for loosely guiding the stem axially relative to the spring, thespring itself being sized to be guided along its length in and by saidbore.

2. The nozzle according to claim 1, wherein at least one of saidconstrictions is in the form of a terminal loop encircling the stem.

3. The nozzle according to claim 1, wherein at least one of saidconstrictions comprises a half round coil portion of the spring, a loopportion encircling the spring, a first straight portion connecting theend of the half round portion tangentially with one end of the loop, asecond straight portion extending tangentially from the other end of theloop, and opposite to said first straight portion, and having alaterally directed terminal extension, said terminal extension and saidcorner portion being located opposite each other and adapted to restupon the adjacent coil of the spring when under compression.

4. The nozzle according to claim 1, wherein at least one of saidconstrictions comprises a coil of reduced diameter interposed betweenadjacent larger coils of the spring.

5. The nozzle according to claim 1, wherein the outlet end of the valvehousing has an external concentric annular groove shaped for theretention therein of a sealing ring of elastically deformable material,with the addition of a sealing ring of elastically deformable materialself-retained in said annular groove, and providing a seat for a valveclosure member.

6. The nozzle according to claim 5, wherein said annular groove extendsalong the outer periphery of said valve body, so that the outerperiphery of the sealing ring therein is outwardly exposed.

7. The nozzle according to claim 1, wherein the inlet end of said valvebody is provided with internal thread.

8. The nozzle according to claim 1, wherein said stem is in the form ofa screw bolt having a head located adjacent the inlet end of said bore.

9. The nozzle according to claim 1, wherein said stem isthread-connected with said closure member.

10. The nozzle according to claim 1, wherein said sealing ring is in theform of an O-ring having circular cross-sectional profile, and saidannular groove extends along the outer periphery of said valve body sothat the outer periphery of said Oring is outwardly exposed.

11. The nozzle according to claim 1, wherein the outlet end of the valvebody has a concentric annular groove, a sealing ring of elasticallydeformable material self-retained in said groove, and providing a seatfor said closure member, wherein said closure member at the undersidethereof is formed with an inverted trunco-conical concentric portion,and wherein the discharge end of said valve portion is formed with aconcentric bevelled face substantially corresponding to the conicity ofsaid trunco-conical portion, and having a clearance relative theretowhen said closure member is seated on said sealing ring.

12. The nozzle according to claim 1, wherein said valve body is in theform of a thick-walled tubular member having the outlet end formed witha peripheral annular outwardly open groove shaped for the retentiontherein of said sealing ring, and wherein the inlet end of said valvebody is provided with internal thread.

13. In an apparatus for the hydraulic upfiow classification of pulps ina teeter bed, a teeter water induction system for the submerged deliveryof teeter water under pressure at the bottom of the liquid bodyrepresenting the teeter bed,

which system comprises substantially horizontally extending duct meanssupplied with operating water under pressure, and having spacedtherealong upwardly directed threaded nipples, a plurality of inductionnozzles for the teeter water connected to respective nipples, and spacedin mutually cooperative relationship to one another for maintaining saidupfiow classification, said nozzles comprising a valve body having avertical axial bore, a threaded inlet end for threaded connection with arespective nipple, and an outlet end having an internal annularshoulder, and also having a concentric annular groove provided in saidoutlet end, and shaped for the retention therein of a sealing ring ofelastically deformable material,

a sealing ring of elastically deformable material selfretained in saidannular groove, and providing a seat for a valve closure member,

a valve closure member for closing said outlet end of the valve body, avalve sealing surface shaped for emitting teeter water radially in alldirections relative to the axis of said bore,

a stem having an outer end connected to said closure member, said stemextending into said bore, and having stop means at its inner end,

and a compression coil spring inserted through the inlet end of saidbore, surrounding said stern and confined between said annular shoulderand said stop means, and effective to allow liquid under pressure to beemitted, and to urge the closure member into closing position when thepressure of the operating water drops, said spring being fonned with aconstriction at each end encircling the stem for loosely guiding thestem axially relative to the spring, the spring itself being sized to beguided along its length by said bore.

14. In an apparatus for the hydraulic upfiow classification of pulp in ateeter bed, a teeter water induction system for the submerged deliveryof teeter water under pressure at the bottom of the liquid bodyrepresenting the teeter bed, which system comprises substantiallyhorizontally extending duct means supplied with operating water underpressure, and having spaced therealong upwardly directed threadednipples, a plurality of induction nozzles for the teeter water connectedto respective nipples and spaced in mutually cooperative relationship toone another for maintaining said upflow classification, said nozzlescomprising a valve body having a vertical axial bore, a threaded inletend for threaded connection with a respective nipple, and a dischargeend having an internal annular shoulder, and also having a concentricexternal annular groove provided in said discharge end, and shaped forthe retention therein of a sealing ring of elastically deformablematerial,

a sealing ring of elastically deformable material selfretained in saidannular groove, and providing a seat for a valve closure member,

a valve closure member for closing said discharge end, having a valvesealing surface shaped for emitting teeter water radially in alldirections, relative to the axis of said bore,

a stem having an outer end which is thread-connected to said closuremember, said stem extending into said bore, and having stop means at itsinner end,

and a compression coil spring inserted through the inlet end of saidbore, surrounding said stem and confined between said annular shoulderand said stop means and efiective to allow teeter water to be emittedhorizontally radially in all directions when the pressure of theoperating water exceeds the combined spring pressure and hydrastaticpressure of the teeter bed, and to urge the closure member into closingposition on said sealing ring when the operating water pressure drops.

15. The induction system according to claim 14, wherein said annulargroove extends along the outer periphery of said valve body, so that theouter periphery of the sealing ring therein is outwardly exposed andaccessible.

16. The induction system according to claim 14, said duct means haveexternally threaded nipples, and wherein the inlet end of said valvebody is provided with internal thread engaging an externally threadednipple.

17. The system according to claim 14, wherein said stem is in the formof a screw bolt having a head located adjacent to the inlet end of saidbore, and wherein said spring has ends of the same diameter, therearward end portion of said spring having an inwardly extending wireportion formed with a loop hugging said stem and engaging said headportion thereby providing a substantially free annular through flow areaaround said head.

18. The system according to claim 14, wherein the rearward end of saidspring has an inwardly extending wire portion formed with a loop huggingsaid stem.

19. The system according to claim 14, wherein the rearward end of saidspring has a constricted portion hugging said stem.

20. The system according to claim 14, wherein said sealing ring is inthe form of an O-ring having circular cross-sectional profile, and saidgroove extends along the outer periphery of said valve body, so that theouter periphery of said O-ring is outwardly exposed and accessible.

21. The system according to claim 14, wherein said closure member at theunderside thereof is formed with an inverted trunco-conical concentricportion, and wherein, the discharge end of said valve body is formedwith a concentric bevelled face substantially corresponding to theconicity of said truncoconical portion, and having clearance relativethereto when said closure member is seated on said sealing ring.

22. The system according to claim 14, wherein said valve body is in theform of a thick walled tubular member having the outlet end formed witha peripheral annular outwardly open groove shaped for the retention ofsaid sealing ring, wherein said duct means have externally threadednipples, and wherein the inlet end of said valve body is provided withinternal thread engaging an externally threaded nipple.

23. A nozzle for the delivery of a liquid supplied under pressure, whichnozzle comprises a valve body having a vertical axial bore with an inletend and an outlet end, and with'an internal annular shoulder formed atthe outlet end of said bore, said valve body also having at the outletend an external concentric annular valve sealing surface shaped foremitting said operating liquid radially in all directions relative tothe axis of said bore,

a stem having an outer end portion connected to said closure member,said stem extending into said bore, and having stop means at its innerend,

and a compression coil spring inserted through the inlet end of saidbore, surrounding said stem and confined between said annular shoulderand said stop means, and effective to allow liquid under pressure to beemitted radially in all directions relative to the axis of said bore,and to urge the closure member into closing position on said sealingring when the liquid pressure drops.

24. The nozzle according to claim 23, wherein said annular grooveextends along the outer periphery of said valve body, so that the outerperiphery of the sealing ring therein is outwardly exposed.

25. The noule according to claim 23, wherein the inlet end of said valvebody is provided with internal thread.

26. The nozzle according to claim 23, wherein said stem is in the formof a screw bolt having a head located adjacent to the inlet end of saidbore, and wherein the rearward end portion of said spring has aninwardly extending wire portion formed with a loop hugging said stem andengaging said head portion, thereby providing a substantially freethrough flow area around said head.

27. The nozzle according to claim 23, wherein the rearward end of saidspring has an inwardly extending wire portion formed with a loop huggingsaid stem.

28. The nozzle according to claim 23, wherein the rearward end of thespring wire has a constricted portion hugging said stem.

29. The nonle according to claim 23, wherein said sealing ring is in theform of an O-ring having circular cross-sectional profile, and saidannular groove extends along the outer periphery of said valve body sothat the outer periphery of said O-ring is outwardly exposed.

30. The nozzle according to claim 23, wherein said closure member at theunderside thereof is formed with an inverted trunco-conical concentricportion and wherein the discharge end of said valve body is formed witha concentric bevelled face substantially corresponding to the conicityof said truncoconical portion, and having clearance relative theretowhen said closure member is seated on said sealing ring.

31. The nozzle according to claim 23, wherein said valve body is in theform of a thick walled tubular member having the outlet end formed witha peripheral annular outwardly open groove shaped for the retentiontherein of said sealing ring, and wherein the inlet end of said valvebody is provided with internal thread.

32. The nozzle according to claim 23, wherein said stem isthread-connected to said closure member.

1. A nozzle for the delivery of a liquid under pressure, which nozzlecomprises a valve body having a vertical axial bore with an inlet endand an outlet end, and with an internal annular shoulder formed at theoutlet end of said bore, a valve closure member for closing said outletend, a stem having an outer end portion connected to said closuremember, said stem extending into said bore, and having stop means at itsinner end, and a compression coil spring inserted through the inlet endof said base, surrounding said stem and confined between said annularshoulder and said stop means, and effective to allow liquid underpressure to be emitted, and to urge the closure member into closingposition when the liquid pressure drops, said spring being formed with aconstriction at each end encircling the stem for loosely guiding thestem axially relative to the spring, the spring itself being sized to beguided along its length in and by said bore.
 2. The nozzle according toclaim 1, wherein at least one of said constrictions is in the form of aterminal loop encircling the stem.
 3. The nozzle according to claim 1,wherein at least one of said constrictions comprises a half round coilportion of the spring, a loop portion encircling the spring, a firststraight portion connecting the end of the half round portiontangentially with one end of the loop, a second straight portionextending tangentially from the other end of the loop, and opposite tosaid first straight portion, and having a laterally directed terminalextension, said terminal extension and said corner portion being locatedopposite each other and adapted to rest upon the adjacent coil of thespring when under compression.
 4. The nozzle according to claim 1,wherein at least one of said constrictions comprises a coil of reduceddiameter interposed between adjacent larger coils of the spring.
 5. Thenozzle according to claim 1, wherein the outlet end of the valve housinghas an external concentric annular groove shaped for the retentiontherein of a sealing ring of elastically deformable material, with theaddition of a sealing ring of elastically deformabLe materialself-retained in said annular groove, and providing a seat for a valveclosure member.
 6. The nozzle according to claim 5, wherein said annulargroove extends along the outer periphery of said valve body, so that theouter periphery of the sealing ring therein is outwardly exposed.
 7. Thenozzle according to claim 1, wherein the inlet end of said valve body isprovided with internal thread.
 8. The nozzle according to claim 1,wherein said stem is in the form of a screw bolt having a head locatedadjacent the inlet end of said bore.
 9. The nozzle according to claim 1,wherein said stem is thread-connected with said closure member.
 10. Thenozzle according to claim 1, wherein said sealing ring is in the form ofan O-ring having circular cross-sectional profile, and said annulargroove extends along the outer periphery of said valve body so that theouter periphery of said O-ring is outwardly exposed.
 11. The nozzleaccording to claim 1, wherein the outlet end of the valve body has aconcentric annular groove, a sealing ring of elastically deformablematerial self-retained in said groove, and providing a seat for saidclosure member, wherein said closure member at the underside thereof isformed with an inverted trunco-conical concentric portion, and whereinthe discharge end of said valve portion is formed with a concentricbevelled face substantially corresponding to the conicity of saidtrunco-conical portion, and having a clearance relative thereto whensaid closure member is seated on said sealing ring.
 12. The nozzleaccording to claim 1, wherein said valve body is in the form of athick-walled tubular member having the outlet end formed with aperipheral annular outwardly open groove shaped for the retentiontherein of said sealing ring, and wherein the inlet end of said valvebody is provided with internal thread.
 13. In an apparatus for thehydraulic upflow classification of pulps in a teeter bed, a teeter waterinduction system for the submerged delivery of teeter water underpressure at the bottom of the liquid body representing the teeter bed,which system comprises substantially horizontally extending duct meanssupplied with operating water under pressure, and having spacedtherealong upwardly directed threaded nipples, a plurality of inductionnozzles for the teeter water connected to respective nipples, and spacedin mutually cooperative relationship to one another for maintaining saidupflow classification, said nozzles comprising a valve body having avertical axial bore, a threaded inlet end for threaded connection with arespective nipple, and an outlet end having an internal annularshoulder, and also having a concentric annular groove provided in saidoutlet end, and shaped for the retention therein of a sealing ring ofelastically deformable material, a sealing ring of elasticallydeformable material self-retained in said annular groove, and providinga seat for a valve closure member, a valve closure member for closingsaid outlet end of the valve body, a valve sealing surface shaped foremitting teeter water radially in all directions relative to the axis ofsaid bore, a stem having an outer end connected to said closure member,said stem extending into said bore, and having stop means at its innerend, and a compression coil spring inserted through the inlet end ofsaid bore, surrounding said stem and confined between said annularshoulder and said stop means, and effective to allow liquid underpressure to be emitted, and to urge the closure member into closingposition when the pressure of the operating water drops, said springbeing formed with a constriction at each end encircling the stem forloosely guiding the stem axially relative to the spring, the springitself being sized to be guided along its length by said bore.
 14. In anapparatus for the hydraulic upflow classification of pulp in a teeterbed, a teeter water induction system for the submerged delivery ofteeter water unDer pressure at the bottom of the liquid bodyrepresenting the teeter bed, which system comprises substantiallyhorizontally extending duct means supplied with operating water underpressure, and having spaced therealong upwardly directed threadednipples, a plurality of induction nozzles for the teeter water connectedto respective nipples and spaced in mutually cooperative relationship toone another for maintaining said upflow classification, said nozzlescomprising a valve body having a vertical axial bore, a threaded inletend for threaded connection with a respective nipple, and a dischargeend having an internal annular shoulder, and also having a concentricexternal annular groove provided in said discharge end, and shaped forthe retention therein of a sealing ring of elastically deformablematerial, a sealing ring of elastically deformable materialself-retained in said annular groove, and providing a seat for a valveclosure member, a valve closure member for closing said discharge end,having a valve sealing surface shaped for emitting teeter water radiallyin all directions, relative to the axis of said bore, a stem having anouter end which is thread-connected to said closure member, said stemextending into said bore, and having stop means at its inner end, and acompression coil spring inserted through the inlet end of said bore,surrounding said stem and confined between said annular shoulder andsaid stop means and effective to allow teeter water to be emittedhorizontally radially in all directions when the pressure of theoperating water exceeds the combined spring pressure and hydrastaticpressure of the teeter bed, and to urge the closure member into closingposition on said sealing ring when the operating water pressure drops.15. The induction system according to claim 14, wherein said annulargroove extends along the outer periphery of said valve body, so that theouter periphery of the sealing ring therein is outwardly exposed andaccessible.
 16. The induction system according to claim 14, said ductmeans have externally threaded nipples, and wherein the inlet end ofsaid valve body is provided with internal thread engaging an externallythreaded nipple.
 17. The system according to claim 14, wherein said stemis in the form of a screw bolt having a head located adjacent to theinlet end of said bore, and wherein said spring has ends of the samediameter, the rearward end portion of said spring having an inwardlyextending wire portion formed with a loop hugging said stem and engagingsaid head portion thereby providing a substantially free annular throughflow area around said head.
 18. The system according to claim 14,wherein the rearward end of said spring has an inwardly extending wireportion formed with a loop hugging said stem.
 19. The system accordingto claim 14, wherein the rearward end of said spring has a constrictedportion hugging said stem.
 20. The system according to claim 14, whereinsaid sealing ring is in the form of an O-ring having circularcross-sectional profile, and said groove extends along the outerperiphery of said valve body, so that the outer periphery of said O-ringis outwardly exposed and accessible.
 21. The system according to claim14, wherein said closure member at the underside thereof is formed withan inverted trunco-conical concentric portion, and wherein the dischargeend of said valve body is formed with a concentric bevelled facesubstantially corresponding to the conicity of said trunco-conicalportion, and having clearance relative thereto when said closure memberis seated on said sealing ring.
 22. The system according to claim 14,wherein said valve body is in the form of a thick walled tubular memberhaving the outlet end formed with a peripheral annular outwardly opengroove shaped for the retention of said sealing ring, wherein said ductmeans have externally threaded nipples, and wherein the inlet end ofsaid valve body is provided with internal thrEad engaging an externallythreaded nipple.
 23. A nozzle for the delivery of a liquid suppliedunder pressure, which nozzle comprises a valve body having a verticalaxial bore with an inlet end and an outlet end, and with an internalannular shoulder formed at the outlet end of said bore, said valve bodyalso having at the outlet end an external concentric annular grooveshaped for the retention therein of a sealing ring of elasticallydeformable material, a sealing ring of elastically deformable materialself-retained in said annular groove, and providing a seat for a closuremember, a valve closure member for closing said outlet end, having avalve sealing surface shaped for emitting said operating liquid radiallyin all directions relative to the axis of said bore, a stem having anouter end portion connected to said closure member, said stem extendinginto said bore, and having stop means at its inner end, and acompression coil spring inserted through the inlet end of said bore,surrounding said stem and confined between said annular shoulder andsaid stop means, and effective to allow liquid under pressure to beemitted radially in all directions relative to the axis of said bore,and to urge the closure member into closing position on said sealingring when the liquid pressure drops.
 24. The nozzle according to claim23, wherein said annular groove extends along the outer periphery ofsaid valve body, so that the outer periphery of the sealing ring thereinis outwardly exposed.
 25. The nozzle according to claim 23, wherein theinlet end of said valve body is provided with internal thread.
 26. Thenozzle according to claim 23, wherein said stem is in the form of ascrew bolt having a head located adjacent to the inlet end of said bore,and wherein the rearward end portion of said spring has an inwardlyextending wire portion formed with a loop hugging said stem and engagingsaid head portion, thereby providing a substantially free through flowarea around said head.
 27. The nozzle according to claim 23, wherein therearward end of said spring has an inwardly extending wire portionformed with a loop hugging said stem.
 28. The nozzle according to claim23, wherein the rearward end of the spring wire has a constrictedportion hugging said stem.
 29. The nozzle according to claim 23, whereinsaid sealing ring is in the form of an O-ring having circularcross-sectional profile, and said annular groove extends along the outerperiphery of said valve body so that the outer periphery of said O-ringis outwardly exposed.
 30. The nozzle according to claim 23, wherein saidclosure member at the underside thereof is formed with an invertedtrunco-conical concentric portion and wherein the discharge end of saidvalve body is formed with a concentric bevelled face substantiallycorresponding to the conicity of said trunco-conical portion, and havingclearance relative thereto when said closure member is seated on saidsealing ring.
 31. The nozzle according to claim 23, wherein said valvebody is in the form of a thick walled tubular member having the outletend formed with a peripheral annular outwardly open groove shaped forthe retention therein of said sealing ring, and wherein the inlet end ofsaid valve body is provided with internal thread.
 32. The nozzleaccording to claim 23, wherein said stem is thread-connected to saidclosure member.